A great deal of information now exists about the synthetic programs of populations of nucleic acids and proteins during the early development of sea urchin embryos, and general features of the molecular events of oogenesis are beginning to accumulate. While such studies provide a comprehensive descriptive framework, virtually nothing is known about the molecular mechanisms of regulation or of the precise details of differential expression of specific sets of developmentally-regulated genes of known function. The sea urchin tubulin gene family provides an especially favorable system for answering several long-standing developmental questions about (1) the levels at which differential expression of specific sets of genes are regulated: transcription, processing, translation, and mRNA stability; (2) the levels of regulation which lead to coordinate synthesis of equal amounts of tubule-specific alpha and beta tubulin pairs; (3) the program of synthesis, storage and translational recruitment of specific subsets of maternal tubulin mRNAs during oogenesis and early development. Recent results from this lab and others show that there are multiple alpha and beta tubulins differing in primary structure which are specific for the various microtubular organelles produced at different development stages: mitotic apparatus tubules, cilia outer pair (A,B) and central pair (CP) tubules, flagellar A,B and CP tubules and membranes tubulin. The developmental program of transcriptional and translational regulation of differential tubulin gene expression will be carried out using cloned alpha and beta cDNA and genomic DNAs recently isolated in our lab. The results of our first studies on the multiplicity and genomic organization of these genes confirm that there are 10-30 different alpha and beta genes, and show that that alpha genes are not linked to beta genes, indicating the specific alpha beta pairs are not coordinately expressed by virtue of their physical linkage. The clones encoding tubule-specific alpha and beta subtypes will be used to ask the following questions: (a) When are maternal tubulin mRNAs synthesized and translationally partitioned during oogenesis? (b) What is the molecular program and mechanism of maternal tubulin mRNA recruitment during early embryonic development? (c) Is selective expression of the different tubulin subtypes regulated at the transcriptional or post-transc (Text Truncated - Exceeds Capacity)